Hydroplane



July 8, 1947. V I PLATT, JR 'Z,423,796

HYDROPLANE Filed March 6, 1946 ZSheets-Sheet l ATTORNEY July 8, 1947. -r, JR 2,423,796

HHHHHHHH NE 6 zsn eeeeeeee t2 Patented July 8, 1947 ITED STATES NT Q FFI'CE HYDROPIYQANE Lester B. mm, In, New York, N. Y. Application March 6, 1946, Serial No. 652,303

This. invention relates to new and useful im-.

prov'e'ments in the construction of the bottoms of boats, preferably of the smaller types of boats andof adesig'n [commonly known as the hydroplane bottom or hull design used in flying boats of pontoons, catamarans, or any similar type of hull that issaid toplane. Characteristic of the design of this. bottom is that it will lend itself to a suggestion of a.four point, suspension? or fW bottom construction, which means that at-high speed this boat rides on the very limited areas indicated by very small shaded portions at the rear inner edges of the outer planing surfaces, in the drawing. V

The essential purpose of this invention is to increase'the speed of a boat, its stability on turns, and its level riding.

Thus, this invention constitutes a combination of the conventional step and the tunnel or seasled design, in addition to other features as will be apparent, as this description proceeds.

The above combination retains the stability of the tunnel design and, due to the angles at which the various riding planes are contacting the surface of the water, a marked. improvement is noted in'the lessening of skin friction by this design over the conventional step design.

With the above and other objects in view, this invention consists of the novel features of construction, combination, and arrangement of parts, hereinafter fully described, claimed, and illustrated in the accompanying drawings, forming part of this specification, and in which similar characters of reference indicate corresponding parts in all views, and in which:

Figure 1 is a plan view of the bottom of a boat, showing my invention.

Figure 2 is a side elevational view of the latter; and

Figure 3 is a frontal view of said bottom proper.

Figure 4 is a View similar to Figure 1, but showing an additional number of tunnels and a plurality of steps in the bottom of the hull; while Figure 5 is a side elevational view of Figure 4.

Referring more particularly to the drawings, Figure 1 is a plan view of the bottom of a boat; said bottom has a step located approximately amidships, as indicated at l l in Figure 2, and by the lines connecting the points H, B, D, C, and I in Figure 1, which lines, in turn, indicate in Figure 3 the relative angles of the different sections.

Thus upon each side of the forward portion of the bottom of the boat, the inversely congruent halves l2, l2 are formed with upwardly and outwardly slanting sides from the lines 13, I3, and

7 Claims. (Cl. 114-665) with portions l4, l4 slanting upwardly and inwardlyfrom said lines l3, l3 towards the center line [5, whereby a. central tunnel is formed by the'said portions l4, l4. 7 I

Viewing next the rearward portion of the bottom of the boat, the inversely congruent halves l6, [6 are formed with upwardly and outwardly slanting sides from the lines ll, I1, and with portions l8, l8 slanting upwardly and inwardly from the linesfl'l', l1 towards the center line l5, whereby a second central tunnel is formed.

It will appear that the edges indicated by lines l3 and I1, and formed by the sections l2, l4 and I 6,, l3, respectively, will form what may be termed steps at acute angles to the flow of the water from how to stern; the water leaving these edges has a. relatively unimpeded path through the tunnels and out the stern.

It has been found desirable from experience to provide the bottom with a step about midship, as indicated at ll, whereby upon release of the water from the forward. tunnel, impetus is given to the bulk of said. water just released, some. of which will fan out, while the rest of the water will continue along the second or rear tunnel.

It will be apparent that the relative angles be,- twe'en the outerportions l2, l2, l6, l6 and the innerportions l4, l4, l8, l8 forming the tunnels may bechan'ged according to the speed and load the boat is desired to carry.

As the speed of the boat is increased, the planes l2, l2 and l6, l6 will lift the boat so that it will be said to plane. At this higher speed the surface of the water supporting the boat will be at a minimum of area, and the boat will be riding on four small triangular areas (especially indicated by transversely dotted lines), denoted by N, or points of suspension at B, C, E and F.

The construction shown in Figures 3 and 4 is identical to the construction shown in Figures 1, 2 and 3, however, an added third, and rearward portion of the bottom in said Figures 3 and 4 shows inversely congruent halves 2|, 2|, formed with upwardly and outwardly slanting sides from the lines 22, 22, and with portions 23, 23, slanting upwardly and inwardly fro-m the lines 22, 22, towards the center line I5, thus forming a third depression or tunnel, and forming also incidentally thereto an additional cross-wise step as indicated by the letters H1, B1, D1, C1 and I1, in Figure 4 and by I l' in Figure 5.

Thus from the drawing it will appear obvious that due to the trailing edges of a series of steps at acute angles to the motion of the water along the bottom, a low pressure area for the escape of the water is provided, and a minimum water surface is in contact with the boat, whereby a higher speed is obtained in addition to a greater load carrying capacity.

While the bottom line I5 is shown herein as straight, said line may be provided with a slight upward curvature towards the bow.

If a partial vacuum is created aft of the steps, as shown, air may be introduced at various points to neutralize said vacuum. Thus, if desired or found necessary, means for eliminating vacuum in the tunnels may be provided, for instance, by tubes, as shown at 20 leading to the upper surface of the boat.

It, has been found that on turns the relative arrangement of the surfaces will have an effect similar to vertical fins toward prevention of side slipping.

It is obvious that slight changes may be made in the form, construction and arrangement of the several parts, as shown, within the scope of the appended claims, without departing from the spirit of my invention, and I do not, therefore,

wish to limit myself to the exact construction and along the top of said triangular cavities being a straight line.

2. In an invention, as claimed in claim 1, and wherein the apex of the triangular cavity commences near the bow of said hull.

3. A boat hull having four pairs of inversely congruent surfaces, and a. straight center line along its bottom, the two inversely congruent surfaces of each of two pairs joining directlyson said center line, the surfaces of said last mentioned two pairs slanting upwardly and inwardly toward the center line forming tunnels in said bottom, triangular in form in plan view, the other two pairs of inversely congruent surfaces more remote from said center line being arranged to form upwardly and outwardly slanting planing surfaces.

4. In an invention, as claimed in claim 3, and wherein the inner edges of the last mentioned outer surfaces directly join the outer edges of the surfaces forming said tunnels.

5. A boat hull having four pairs of inversely congruent surfaces, and a straight center line along its bottom, the two inversely congruent surfaces of each of two pairs joining directly on said center line, the surfaces of said last mentioned two pairs slanting upwardly and inwardly toward the center line forming tunnels in said bottom, triangular in form in plan view, the other two pairs of inversely congruent surfaces more remote from said center line being arranged to form'upwardly and outwardly slanting planing surfaces, said surfaces forming rapidly and proportionally diminishing triangula plane areas of support upon increasing the speed of the boat.

6. An invention, as claimed in claim 5, and wherein the apex of a rear tunnel joins the one in front thereof at substantially the greatest width of the latter.

7. A boat hull having a plurality of sets of inversely congruent surfaces, each set of the latter being arranged with one of said surfaces upon each side of a straight center line, a plurality of steps cross-wise arranged with respect to the bottom, each step forming a set-off between each set of inversely congruent surfaces, the latter surfaces forming tunnels triangular in plan View, the sides of said tunnels slanting upwardly and inwardly towards the common center line, and the apex of each tunnel joining the one in front thereof at substantially the greatest width of the latter.

LESTER B. PLATT, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,637,677 Bonnemaison Aug. 2, 1927 1,204,355 Hickman Nov. 7, 1916 FOREIGN PATENTS Number Country 7 Date 831,335 France Aug. 30, 1938 

